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SCAN Tool

The SCAN Tool incorporates state-of-the-art wellbore acoustics theory and measurement technology to deliver highly accurate acoustic data in through-casing applications. The SCAN tool locates Water-Oil-Gas fluid contacts and corresponding saturation when combined with the MDNT (Memory Dual Neutron Tool). The acoustic-based SCAN tool is unaffected by casing hardware and has a deep depth of investigation.

The velocity of compressional and acoustic waves can be used to determine the type of saturation fluid, and is most effective in less well-consolidated formations. In these sediments, the compressional wave velocity is strongly influenced by the type of saturating fluid. The shear velocity is unaffected.

Description

The tool is a multi-receiver 1 11/16" acoustic tool designed to investigate through-tubing fluid contacts, by measuring P- and S-wave reflections from the fluid formation.

Features
  • High energy pulsed-power transmitters
  • Low frequency/high energy (deeper penetration/stronger signal)
  • Downhole automatic gain control
  • Multiple presentation formats
Tool Specifications
Tool Outside Diameter 40 mm (1.6 in)
Length Variable (depending on configuration)
Maximum Temperature 150 °C
Maximum Pressure 200 bars
Variable Spacing All traces synchronously and simultaneously recorded
Sonic Wave Frequency 15 - 25 kHz
Sonic Wave sampling rate Configurable, 2 - 50 msecs
Sonic Wave Length Configurable, up to 1024 samples  per receiver
Dynamic range 12 bits plus 4 bits gain (configurable) including AGC
Data communication High Speed telemetry
Modular tool allowing a configuration of up to 2 transmitters and 8 receivers:
  1. Transducers
    • Types: Monopole and Multi-pole
  2. Transmitters
    • Quantity: 2
    • Spacing: 30 in (762 mm)
  3. Receivers
    • Quantity: 8
    • Spacing: 6.0 in (152.4 mm)
    • T1R1 Offset: 11.0 ft (3.2 m)
LOG-MEASUREMENT SPECIFICATIONS
  • Minimum Borehole Diameter: 4.5 in (114 mm)
  • Maximum Borehole Diameter: 21 in (533 mm)
  • Recommended Logging Speed: 5 - 10 ft/min high  resolution mode
  • Lower Porosity Limit: 14%
  • Transmitter Firing: 1 or 2 per second
  • Oil-Water contact determination limits: 40 API
  • Resolution: 1/8 of a wavelength
APPLICATIONS
  • Through-tubing identification of Water-Oil-Gas contacts
  • Lithology and Hydrocarbon typing
  • Waterflood/supplemental recovery surveillance
  • Volumetrics (porosity/water saturation) behind the casing
  • Direct measurement of rock mechanical properties (elastic  moduli/compressibilty)
  • Highly accurate measurement of compressional, shear and stoneley wave  velocities/travel times
RESERVOIR FLUID IDENTIFICATION

The crossplot of Vp/Vs vs Dt shear has proven to be a hydrocarbon indicator in homogeneous plastics. This technique is based on the principle that formation compressional travel times are reduced in relation to the compressible reservoir fluid saturation, while shear travel times remain generally unchanged.

View Acoustic Lithology and Porosity chart in PDF format
View Shear Wave and Porosity relation in PDF format

If you are interested in this service, please fill out our Service Request Form, and we will get back to you promptly.

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Case Histories

Oildata was the first company to successfully record a horizontal well Production Log on an ExxonMobil Well in West Africa

– Ubit 71, Ubit 75, 1995

The first service company to log a memory log on a short Radius horizontal well in Africa.

– Ashland, 1997

Oildata was the first company to design and install an open-close-open straddle packer system to isolate a high pressure gas zone while simultaneously permitting the production of oil from a deeper horizon.

– ChevronTexaco, 1998, 1999

Oildata was the first company to deploy a wireline tractor in a horizontal well in Nigeria to acquire reservoir data without coiled tubing or pipe conveyed logging equipment.

– Shell, 1999

Oildata successfully re-established oil production from the abandoned Salt pond Marginal field, offshore Ghana.

– SOPC/GNPC, 2002

Oildata has performed 100% of ChevronTexaco's non-rig well interventions and data acquisition requirements in Nigeria since 1996

– ChevronTexaco, 1996

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